Filter pack and method of and apparatus for making same



'Junen. 1940. o. DAHL Em FILTER PACK AND HETHOD OF AND APPARATUS FOR MAKING SAME Filed latch 15, 1939 2 Sheets-Sheet 1 J M 8222 M22 0 004/ ORNEYfi.

June 11, 1940. Q DAHL AL 2,203,815

FILTER PACK AND IETHDD OF AND APPARATUS FOR MAKIFG SAME Filed larch 15. 1959 2 Sheets-Sheet 2 mwzzvroks ATTORNEYJ.

Patented June 11, 194Q FILTER PACK AND METHOD OF AND APPARATUS FOR MAKING SAME Otto Dahl and Stanley Douglas Osborn, Spokane,

Wash.

Application March 15, 1939, Serial No. 262,054

7 Claims.

This invention relates to a filter pack and method of and apparatus for forming the same,

and particularly relates to a filter pack intended for use in the casing of a filter by means of which the lubricating oil of an engine is filtered and thus cleared of dirt and other foreign matter so that use of the oil may be continued over a long period of time. One object of the invention is to provide a filter pack including a core of screening mounted about a perforated tube of special formation, and layers of cotton or other fibrous material through which oil passes before reaching the screening and passing through the screening to the inlet perforations of the tube, the cotton batting or Waste and the coil of screening being firmly held in place about the tube and prevented from slipping out of proper relation thereto.

U Another object of the invention is to provide a filter pack wherein the coil of wire screening and layers of cotton batting or waste are each bound with cord to compress and confine them and thus preserve their density and dimensions and cause the oil to be properly filtered in a very eflicient manner.

Another object of the invention is to provide a filter pack of such formation that the fabric layers about the wire screening and the tube are l 1 enclosed in a covering formed of strips of woven fabric which are soapplied that they will be firmly held smoothly against the outer layer of fabric.

Another object of the invention is to provide 85 an improved mechanism for carrying the tube during formation of the filter pack and drawing the tube and layers of fabric covering the same, downwardly into a cylinder during application of the fabric strip to cover the fabric 40 layers and enclose the same.

The invention is illustrated in the accompanying drawings, wherein:

Fig. 1 is a view partially'in elevation andpartially in vertical section, showing a filter pack of the improved construction partially formed.

Fig. 2 is a fragmentary view showing the partially formed filter pack in elevation and portions of the apparatus in vertical section.

Fig. 3 is a fragmentary view showing the pack moved downwardly into the cylinder of the apparatus and ends of fabric stripsforming the outer covering of the pack bound together at the top of the pack. 55 Fig. 4 is a view similar to Fig. 3, showing the pack' shifted upwardly during application of a binding cord.

Fig. 5 is a view showing the pack shifted upwardly out of the cylinder and the binding cord completely applied. 5

Fig. 6 is a view of the finished pack. Fig. 7 is a view on an enlarged scale showing the filter pack partially in elevation and partially in longitudinal section.

Fig. 8 is a view showing the tube in elevation. 10 Fig. 9 is a sectional view taken transversely through the filter pack, on the line 9-9 of Fig. 7. A This improved filter pack is for use in a filter employed as means for removing dirt and other foreign matter from the lubricating oil of an 15 engine and is to be mounted in a casing with the threaded end I of the perforated tube 2 screwed into the outlet of the casing. Therefore, oil entering the casing through an inlet opening and seeping through the filter pack, may enter the tube through the inlet openings or perforations 3 as clean oil and flow from the lower end of the tube into a pipe constituting a portion of the lubricating system of the engine and delivered in a clean state to bearings of the engine.

The upper end portion 4 of the tube is solid, as shown in Fig. 7, and terminates in a squared end 5 for engagement by a wrench when screwing the lower end of the tube into the outlet opening of the filter casing. Upper and lower annular flanges or collars Esurround the tube in spaced relation to its ends and, between the upper flange and the squared end 5, the tube carries a pin 1 which passes transversely through the solid upper portion of the tube and constitutes an anchoring member having portions projecting from opposite sides of the tube.

The tube is surrounded by filtering material and, upon referring to Fig. 7, it will be seen that a sheet 8 of coarse woven wire is first wound about the tube between the fian'ges 6 in shielding relation to the inlet perforations 3. This coarse screening is secured by cord 9 which is wound about it and a sheet ill of fine screening is then coiled about the coarse screening and secured by cord Qrstring ll wound about it. A sheet l3 of coarse fabric surrounds the fine wire screening with its upper and lower portions projecting beyond the collars and bound tightly about upper and lower portions of the tube by end portions M of the cord I 4 which is wound about the fabric spirally thereof. The coarse screening 8 and the fine screening 9 serve as shields for the perforations in the tube and very bound by cord I8, and an outer layer I9 bound by cord 20. The layer I5 is of soft cotton batting, the intermediate layer of waste having ab- 'sorbent qualities, and the outer layer is also formed of waste. Oil may seep through the layers or wrappings l5, l1 and I9, but dirt and other foreign matter will be held back and only clean oil will pass through the screening and enter the tube 3 through the inlet perforations thereof.

' As the screening will hold back any lint or the tightly bound to the tube between these collars and ends of the tube, serve to prevent any dlirty oil from working along the tube and reaching the inlet perforations 3 of the tube.

A length of rope 2| formed of cotton waste is coiled about the tube under the lower collar.

and lower ends of the fibrous layers of cotton batting and waste, and this cotton rope is compressed by'the fabric covering 22 enclosing the fibrous layers to form 'a tight packing which.

assists in preventing oil from working upwardly along the tube. The fabric covering'22 consists of fabric strips extending longitudinally of the filter pack in overlapping relation to each other and firmly secured by a circumferentially extending binding 24 formed of cord wound spirally about the cover and a companion binding 25 formed of cord extending longitudinally of the filter pack. The completed filter pack is of compact substantially cylindrical formation and ends of the tube project therefrom so that when the filter pack is installed for use it may be thrust into the casing of a filter through an open end thereof and the threaded lower end I of the tube screwed into a threaded outlet opening of the filter casing through the medium of a wrench engaged with the squared upper end portion 5 of the tube.

During formation of the improved filter pack, the apparatus illustrated in Fig. 1 is employed and the steps shown in Figs. 1 through 6 followed.. -;Referring to Fig. .1, it will be seen that during the formation of the filter pack the threaded lower end portion of the tube is screwed into a threaded socket 26 formed at the center of a. piston 21 which is slidably received within a vertically disposed cylinder 28. This cylinder is mounted vertically in a frame 29 with its lower end engaging a yoke 30 having a bearing sleeve 3| through which slidably passes a threaded shaft 32. The shaft 32 extends through the cylinder axially thereof and its upper end is secured to the'depending lugs 33 ofthe piston 21 by a pin 34. The base 35 of the 'frame carriesa bearing 36 through which the ,shaft 32 is slidably received, and. the base is formed with an opening 31 through which the shaft passes when shifted downwardly to lower the piston in the cylinder. A worm gear 38, which has threaded engagement with the shaft 32, is rotatably mounted between the sleeve and the bearing 36 upon which it rests and this worm gear meshes with a worm 39 carried by the shaft of a reversing motor 40 mounted upon the base 35. By employing a reversing 'motor, directional rotation of the worm gear may be controlled and the shaft 32 shifted longitudinally to lower or raise the piston.

The coarse screening and the fine screening are applied to the tube 2 and secured by the binding cords 9 and II, after which the heavy fabric I3 is applied and secured by the cord l4 which, in addition to securing the fabric about the screenings; also serves to tightly bind por-.

tions of the fabric in close contacting engagement with the tube aboveand below the collars 6. The threaded end of the tube is then screwed tightly into the socket of the piston which is at the upper end of the cylinder 28. Before screwing the tube into the socket, it is passed through registering openings formed midway the length of the fabric strips 23 which'are disposed across the upper end of the cylinder with portions of the strips resting upon the platform or table 40 at the top of the frame 29. The rope 2| formed of cotton waste is wrapped about the lower portion of the tube, as shown in Fig. l, and the layers of cotton batting l5 and waste l1 and I9 then applied and secured by their binding cords I6, l8 and 20. If so desired, the layers of cotton and waste may be applied and then the cotton rope. The strips of fabric 23 are then brought into covering relation to the outer layer of waste by starting the motor and turning the gear 38 in a direction to shift the shaft 32 and piston 21 downwardly in the cylinder 28. This not only disposes the strips longitudinally of the filter pack but, in addition, holds their side edge portions in overlapping relation to each other while the free upper ends of the strips are brought together and twisted, as shown at 4|, the twisted e ds of the strips being temporarily secured by a ubber band 42. At this time, the filter pack will be housed in the cylinder, as shown in Fig. 3, with the piston at the lower end of the cylinder. The motor is then reversed to shift the shaft and the piston upwardly and eject' the filter pack from the cylinder. 'During this upward movement of the piston, the cord 24 is wound about the outer covering 22 formed by the strips 23, the cord 3 inder, as shown in Fig. 5, the motor is shut off and the filter pack bound longitudinally by the cord 24. The twisted ends 4| of the strips 23 are cut off to expose the squared upper end portion of the tube and the tube is' then unscrewed from the socket of the piston. The filter pack is then completed and ready for use.

Having thus described the invention, what is claimed is: 1. A filter pack comprising a perforated tube having a closed upper end, collars surrounding said tube in spaced relation to its ends, a pin passing through said tube and spaced from the upper collar and the upper end of the tube. screening about said tube between said collars. fabric covering said screening with portions projecting beyond said collars and bound tightly about the tube, an inner wrapping of cotton batting about said fabric, an intermediate wrapping of waste about said inner wrapping, an outer wrapping of waste about said intermediate wrapping, each wrapping being bound with cord, said pin having accents in upper portions of said wrappings to anchor end detachably mounted in an outlet of a filter casing.

2. A filter pack comprising a tube having its lower end open and threaded for engagement in an outlet of a filter casing and its upper end solid and formed with wrench-engaging faces, annu-- lar collars carried by said tube in spaced relation to its upper and lower ends, perforations in said tube between said collars, coarse metal screening wrapped about said tube between said collars, fine metal screening about the coarse screening, a fabric wrapping covering the fine metal screening, inner, outer and intermediate layers of flbrous filtering material about the fabric wrapping projecting beyond said collars, cotton rope wound about said tube under the lowercollar and enclosed by the lower portions of the layers of filtering material, and a fabric coveringfor the outer layer of fibrous filtering material.

3. A filter pack comprising a tube open at itslower end and closed at its upper end, collars carried by said tube, the portion of the tube between said collars being perforated, metal screening about the perforated portion of said tube, fabric covering said screening and having portions projecting from said collars and bound tightly about end portions of the tube, layers of fibrous filtering material about the fabric, strips of fabric extending longitudinally of the filter pack in overlapped relation to each other and forming a fabric cover for the fibrous filtering material, and means for securing said strips in place.

4. A filter pack comprising a tube open at one end and closed at its other end, said tube being perforated for a portion of its length, metal screening about the perforated portion of said tube, fabric covering said screening, an anchoring pin passing transversely through said tube in spaced relation to the closed end of the tube, a length of soft fibrous material wound tightly about the tube in spaced relation to the open end of the tube in sealing relation to the, perforated the same and also enclosing the wound length of fibrous material, and fabric enclosing the soft fibrous filtering material.

5. The method of forming a filter pack consisting of removably mounting a perforated tube in a vertical position, securing. wire screening about the perforated tube, covering the wire screening with fabric having portions extending from ends of the screening, binding the extended portions of the fabric in close contacting engagement with the tube, disposing soft fibrous filtering 'material in layers about the covered screening, covering the fibrous filtering material with strips of fabric extending longitudinally of the filter pack with side portions of'the strips overlapped, and applying binding cord to hold the strips in confining and compressing relation to the filtering material.

6. The method of forming a filter pack consisting of placing strips of fabric in overlapped relation to each other across the upper end of a vertically disposed cylinder in which a support is mounted for vertical movement, passing an end of a perforated tube through overlapped portion of the fabric strips and removably engaging the tube with the support to mount the tube vertically, wrappingwire screening about the perforated tube, covering the screening with woven fabric, applying layers of soft fibrous filtering material about the covered screening, shifting the support downwardly in the cylinder to cause said strips to be moved into covering relation to the filtering material, twisting upper ends of the strips together above the upper end of the tube and securing the twisted end portions together about the upper end of the tube, shifting the support upwardly to move the filter pack upwardly out'of the cylinder and while doing so wrapping a binding cord about the fabric covering formed by the strips, applying a binding cord longitudinally of the filter pack, removing the twisted together end portions of the fabric strips, and detaching the tube from the support.

7. The method set forth. in claim 6, wherein soft rope is wrappedtightly about the tube between the lower end of the covered screening and the portions of the strips through which thetube passes, the said rope being enclosed and compressed by the strips to form a seal about the lower portion of the tube.

OTI'O DAHL. S. DOUGLAS OSBORN.

iii 

